N-Functionalised TsDPEN catalysts for asymmetric transfer hydrogenation; synthesis and applications

Homologation of aryl ketones to long-chain ketones and aldehydes via C-C bond cleavage

Transition metal-catalyzed C-C bond cleavage is a powerful tool for the reconstruction of a molecular skeleton. We report herein the multi-carbon homologation of aryl ketones to long-chain ketones and aldehydes via ligand-promoted Ar-C(O) bond cleavage and subsequent cross coupling with alkenols. Various (hetero)aryl ketones are compatible in the reaction, affording the corresponding products wtih good to excellent yields with high regioselectivity. Further applications in the late-stage diversification of biologically important molecules demonstrate the synthetic utility of this protocol. Mechanistic studies indicate that the ligand plays an important role in both C-C bond cleavage and the asymmetric migration-insertion process.

Synthesis and Biological Evaluation of Subglutinol Analogs for Immunomodulatory Agents

Autoimmune diseases are chronic inflammatory diseases associated with high morbidity and mortality. Treatment options for autoimmune diseases have increased over the past several decades, but they are, in general, limited in their clinical efficacy due to high toxicity and lack of selectivity. Thus, efforts must be made to identify new immunomodulatory agents that are effective through a novel mechanism to circumvent existing side effects. To define the structural requirements of subglutinols for immunomodulatory activity and to provide guiding principles on future therapeutic development, we prepared and evaluated several subglutinol analogs for their immunomodulatory activities. Our efforts identified a subglutinol analog with reduced structural complexity as a potential lead compound for future autoimmune drug development. Our study will provide an important framework for the design of potent and nontoxic immunomodulating agents derived from subglutinols.

Probing the Effects of Heterocyclic Functionality in [(Benzene)Ru(TsDPENR)Cl] Catalysts for Asymmetric Transfer Hydrogenation

A range of TsDPEN catalysts containing heterocyclic groups on the amine nitrogen atom were prepared and evaluated in the asymmetric transfer hydrogenation of ketones. Bidentate and tridentate ligands demonstrated a mutual exclusivity directly related to their function as catalysts. A broad series of ketones were reduced with these new catalysts, permitting the ready identification of an optimal catalyst for each substrate and revealing the subtle effects that changes to nearby donor groups can exhibit.

Applications of N′-monofunctionalised TsDPEN derivatives in asymmetric catalysis

N′-Monoalkylated or N′-mono(thio)acylated(N-sulfonyl)-1,2-diphenylethylene-1,2-diamine (TsDPEN) derivatives are have found extensive applications in asymmetric catalysis of a wide range of synthetic applications.

The mechanism of enantioselective ketone reduction with Noyori and Noyori–Ikariya bifunctional catalysts

The present article describes the current level of understanding of the mechanism of enantioselective hydrogenation and transfer hydrogenation of aromatic ketones with pioneering prototypes of bifunctional catalysts, the Noyori and Noyori–Ikariya complexes.